Binder composition for non-aqueous secondary battery electrodes, slurry composition for non-aqueous secondary battery electrodes, electrode for non-aqueous secondary batteries, and non-aqueous secondary battery

Abstract

The present invention provides a binder composition for non-aqueous secondary battery electrodes, which is capable of forming a non-aqueous secondary battery having excellent high temperature storage characteristics and low internal resistance. This binder composition for non-aqueous secondary battery electrodes contains a particulate polymer and water. The particulate polymer contains a polymer containing an aromatic vinyl monomer unit and a conjugated diene monomer unit, the value of the loss tangent tanδ is not less than 0.001 but less than 0.40, and the gel content is more than 75 mass% but not more than 99.9 mass%.

Description

Binder composition for non-aqueous secondary battery electrodes, slurry composition for non-aqueous secondary battery electrodes, electrodes for non-aqueous secondary batteries, and non-aqueous secondary batteries

[0001] The present invention relates to a binder composition for a non-aqueous secondary battery electrode, a slurry composition for a non-aqueous secondary battery electrode, an electrode for a non-aqueous secondary battery, and a non-aqueous secondary battery.

[0002] Non-aqueous secondary batteries such as lithium ion secondary batteries (hereinafter sometimes simply referred to as "secondary batteries") are small, lightweight, have high energy density, and are capable of repeated charge and discharge, and are therefore used in a wide range of applications. Therefore, in recent years, improvements to battery components such as electrodes have been investigated with the aim of further improving the performance of non-aqueous secondary batteries.

[0003] An electrode used in a secondary battery typically includes a current collector and an electrode mixture layer (positive electrode mixture layer or negative electrode mixture layer) formed on the current collector. The electrode mixture layer is formed, for example, by applying a slurry composition containing an electrode active material and a binder composition containing a binding agent onto the current collector and then drying the applied slurry composition.

[0004] Therefore, in recent years, attempts have been made to improve the binder compositions used in forming electrode mixture layers in order to achieve further improvements in the performance of secondary batteries. Specifically, for example, Patent Document 1 proposes a binder composition capable of forming electrodes with excellent peel strength after exposure to high temperatures and secondary batteries with low internal resistance, the binder composition including a polymer containing aromatic vinyl monomer units, conjugated diene monomer units, and hydrophilic monomer units, and having loss tangent tanδ and loss modulus G″ values ​​within predetermined ranges. Furthermore, for example, Patent Document 2 proposes a binder composition for non-aqueous secondary battery negative electrodes capable of forming negative electrode mixture layers with excellent peel resistance, the binder composition including a polymer containing ethylenically unsaturated carboxylic acid monomer units, aromatic vinyl monomer units, and aliphatic conjugated diene monomer units, and having a degree of swelling in tetrahydrofuran and a tetrahydrofuran insoluble content within predetermined numerical ranges, and a ratio of the viscosity at pH 8.0 to the viscosity at pH 3.0 when the solids concentration is 30% by mass within predetermined numerical ranges.

[0005] International Publication No. WO 2022 / 114199 International Publication No. WO 2023 / 008100

[0006] However, the conventional binder compositions described above have room for improvement in terms of further reducing the internal resistance of secondary batteries and improving their high-temperature storage characteristics.

[0007] Therefore, an object of the present invention is to provide a binder composition for non-aqueous secondary battery electrodes and a slurry composition for non-aqueous secondary battery electrodes that can form non-aqueous secondary batteries with excellent high-temperature storage characteristics and low internal resistance. Another object of the present invention is to provide an electrode for a non-aqueous secondary battery that can form a non-aqueous secondary battery with excellent high-temperature storage characteristics and low internal resistance. A further object of the present invention is to provide a non-aqueous secondary battery with excellent high-temperature storage characteristics and low internal resistance.

[0008] The present inventors have conducted extensive research to solve the above-mentioned problems, and have newly discovered that a nonaqueous secondary battery electrode binder composition containing water and a particulate polymer including a polymer containing aromatic vinyl monomer units and conjugated diene monomer units, and having a loss tangent tanδ and a gel content within predetermined ranges, can provide a nonaqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance, thereby completing the present invention.

[0009] The present invention aims to solve the above-mentioned problems. [1] The binder composition for a non-aqueous secondary battery electrode of the present invention (hereinafter sometimes simply referred to as the "binder composition") comprises a particulate polymer and water. The particulate polymer comprises a polymer containing aromatic vinyl monomer units and conjugated diene monomer units, and is characterized by having a loss tangent tanδ of 0.001 or more and less than 0.40, and a gel content of more than 75% by mass and less than 99.9% by mass. Thus, by using a binder composition containing a particulate polymer containing a polymer containing aromatic vinyl monomer units and conjugated diene monomer units and having a loss tangent tanδ and gel content within the specified ranges, a non-aqueous secondary battery having excellent high-temperature storage properties and low internal resistance can be obtained. Here, in the present invention, the "monomer unit" of a polymer means "a repeating unit derived from that monomer contained in a polymer obtained using that monomer." In the present invention, the "loss tangent tan δ" and "gel content" of the non-aqueous secondary battery electrode binder composition can be measured according to the method described in the examples of this specification.

[0010] [2] In the binder composition for a non-aqueous secondary battery electrode described in [1] above, the ratio (Da / Db) of the volume average particle diameter Da of the particulate polymer measured by laser diffraction scattering at a solids concentration of 0.1% by mass to the average particle diameter Db of the particulate polymer measured by dynamic light scattering at a solids concentration of 0.005% by mass is preferably 1.4 or more and 2.0 or less. When the ratio (Da / Db) of the volume average particle diameter Da to the average particle diameter Db is equal to or greater than the lower limit, the high-temperature storage characteristics of the resulting non-aqueous secondary battery can be further improved. Furthermore, when the ratio (Da / Db) of the volume average particle diameter Da to the average particle diameter Db is equal to or less than the upper limit, the cycle characteristics of the resulting non-aqueous secondary battery can be improved. In the present invention, the solids concentration of the binder composition for a non-aqueous secondary battery electrode when measuring the "volume average particle diameter Da" and "average particle diameter Db" can be adjusted by adding or removing water. In the present invention, the "volume average particle diameter Da" and the "average particle diameter Db" of the particulate polymer can be measured according to the method described in the examples of this specification.

[0011] [3] In addition, the binder composition for a non-aqueous secondary battery electrode according to the above [1] or [2] preferably has a loss tangent tanδ of 0.15 or more. If the loss tangent tanδ is 0.15 or more, the high-temperature storage characteristics of the obtained non-aqueous secondary battery can be further improved and the internal resistance can be further reduced.

[0012] Furthermore, [4] in the binder composition for a non-aqueous secondary battery electrode according to any one of [1] to [3] above, it is preferable that the particulate polymer contains a polymer A containing aromatic vinyl monomer units and conjugated diene monomer units, and a polymer B containing aromatic vinyl monomer units and conjugated diene monomer units and different from the polymer A. If the particulate polymer contains two or more types of polymers, the high-temperature storage characteristics of the resulting non-aqueous secondary battery can be further improved and the internal resistance can be further reduced. In the present invention, the phrase "polymer A and polymer B are different" means that they are different in at least one of their composition and properties.

[0013] [5] In the binder composition for a non-aqueous secondary battery electrode according to any one of [1] to [4] above, the particulate polymer preferably has an electrolyte swelling degree of 300% by mass or less. If the particulate polymer has an electrolyte swelling degree of 300% by mass or less, the output characteristics and cycle characteristics of the resulting non-aqueous secondary battery can be improved. In the present invention, the "electrolyte swelling degree" of the particulate polymer can be measured according to the method described in the examples of this specification.

[0014] Another object of the present invention is to solve the above-mentioned problems, and provides [6] a slurry composition for a non-aqueous secondary battery electrode (hereinafter sometimes simply referred to as "slurry composition") of the present invention, which is characterized by containing an electrode active material and the binder composition for a non-aqueous secondary battery electrode described in any one of [1] to [5] above. By using a slurry composition for a non-aqueous secondary battery electrode containing the above-mentioned binder composition for a non-aqueous secondary battery electrode, a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance can be obtained.

[0015] [7] In the slurry composition for a non-aqueous secondary battery electrode according to the above [6], the electrode active material preferably contains a silicon-based negative electrode active material. Use of an electrode active material containing a silicon-based negative electrode active material can improve the output characteristics and capacity of the resulting non-aqueous secondary battery.

[0016] Furthermore, the present invention aims to solve the above-mentioned problems, and provides [8] a non-aqueous secondary battery electrode (hereinafter sometimes simply referred to as "electrode") of the present invention, which comprises a current collector and an electrode mixture layer located on the current collector, characterized in that the electrode mixture layer is a layer formed from the slurry composition for a non-aqueous secondary battery electrode described above in [6] or [7]. By using a non-aqueous secondary battery electrode having a layer formed from the above-mentioned slurry composition for a non-aqueous secondary battery electrode, a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance can be obtained.

[0017] The present invention aims to solve the above-mentioned problems, and provides a nonaqueous secondary battery [9] comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode and the negative electrode is the nonaqueous secondary battery electrode described in [8] above. By using the nonaqueous secondary battery electrode described above for at least one of the positive electrode and the negative electrode, a nonaqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance can be obtained.

[0018] According to the present invention, it is possible to provide a binder composition for a non-aqueous secondary battery electrode and a slurry composition for a non-aqueous secondary battery electrode, which are capable of forming a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance. Also, according to the present invention, it is possible to provide an electrode for a non-aqueous secondary battery, which is capable of forming a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance. And according to the present invention, it is possible to provide a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance.

[0019] Hereinafter, embodiments of the present invention will be described in detail. The binder composition for a non-aqueous secondary battery electrode of the present invention can be used to prepare a slurry composition for a non-aqueous secondary battery electrode. The slurry composition for a non-aqueous secondary battery electrode prepared using the binder composition for a non-aqueous secondary battery electrode of the present invention can be used to form an electrode (a non-aqueous secondary battery electrode) for a non-aqueous secondary battery such as a lithium-ion secondary battery. Furthermore, the non-aqueous secondary battery of the present invention is characterized by using a non-aqueous secondary battery electrode formed using the slurry composition for a non-aqueous secondary battery electrode of the present invention. The binder composition for a non-aqueous secondary battery electrode and the slurry composition for a non-aqueous secondary battery electrode of the present invention are particularly suitable for use in forming a negative electrode for a non-aqueous secondary battery.

[0020] (Binder composition for non-aqueous secondary battery electrodes) The binder composition for non-aqueous secondary battery electrodes of the present invention comprises a particulate polymer and water as a dispersion medium, and optionally further comprises other components that can be incorporated into electrodes of secondary batteries. Furthermore, in the binder composition for non-aqueous secondary battery electrodes of the present invention, the particulate polymer comprises a polymer containing aromatic vinyl monomer units and conjugated diene monomer units. Furthermore, the binder composition for non-aqueous secondary battery electrodes of the present invention has a loss tangent tanδ value of 0.001 or more and less than 0.40, and a gel content of more than 75 mass% and not more than 99.9 mass%.

[0021] Furthermore, according to the binder composition for a non-aqueous secondary battery electrode of the present invention, the particulate polymer contains a polymer containing aromatic vinyl monomer units and conjugated diene monomer units, and the value of loss tangent tanδ and the gel content of the binder composition are within the above-mentioned ranges. Therefore, the internal resistance of a secondary battery including an electrode formed using the binder composition can be reduced, and the secondary battery can exhibit excellent high-temperature storage characteristics.

[0022] <Particulate Polymer> The particulate polymer is a component that can function as a binder to prevent components such as an electrode active material from detaching from an electrode mixture layer formed using a slurry composition containing a binder composition. The particulate polymer must contain a polymer containing aromatic vinyl monomer units and conjugated diene monomer units, and may optionally further contain other polymers (e.g., a polymer that does not contain aromatic vinyl monomer units and conjugated diene monomer units, and a polymer that contains only one of aromatic vinyl monomer units and conjugated diene monomer units). The particulate polymer may contain only one type of polymer containing aromatic vinyl monomer units and conjugated diene monomer units, or may contain two or more types. The polymer contained in the particulate polymer is usually a water-insoluble polymer, and when 0.5 g of the polymer is dissolved in 100 g of water at 25 ° C, the insoluble content may be 90 mass % or more.

[0023] [Polymer] The polymer contains aromatic vinyl monomer units and conjugated diene monomer units, and may optionally contain other monomer units.

[0024] -Aromatic vinyl monomer unit- Examples of aromatic vinyl monomers that can form aromatic vinyl monomer units include aromatic monovinyl compounds such as styrene, styrene sulfonic acid and its salts, α-methylstyrene, p-t-butylstyrene, butoxystyrene, vinyltoluene, chlorostyrene, and vinylnaphthalene. Among these, styrene and its derivatives are preferred, and styrene is more preferred. These can be used alone or in combination of two or more.

[0025] The proportion of aromatic vinyl monomer units contained in the polymer is preferably 1% by mass or more, more preferably 3% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, when the amount of all monomer units in the polymer is 100% by mass.

[0026] - Conjugated diene monomer unit - Examples of conjugated diene monomers that can form conjugated diene monomer units include aliphatic conjugated diene compounds having 4 or more carbon atoms, such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Among these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred. These can be used alone or in combination of two or more. By using 1,3-butadiene to form conjugated diene monomer units of a polymer, the dispersion stability and thermal stability of the resulting polymer can be improved.

[0027] The proportion of the conjugated diene monomer units contained in the polymer is preferably 25% by mass or more, more preferably 30% by mass or more, and is preferably 99% by mass or less, more preferably 95% by mass or less, when the amount of all monomer units in the polymer is 100% by mass.

[0028] Other Monomer Units The other monomer units that can be contained in the polymer are not particularly limited, and examples thereof include an acidic group-containing monomer unit and an amide group-containing monomer unit.

[0029] Examples of acidic group-containing monomers capable of forming acidic group-containing monomer units include carboxylic acid group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers.

[0030] Examples of carboxylic acid group-containing monomers include monocarboxylic acids and their derivatives, dicarboxylic acids and their acid anhydrides, and derivatives thereof. Examples of monocarboxylic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of monocarboxylic acid derivatives include 2-ethylacrylic acid, isocrotonic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, and α-chloro-β-E-methoxyacrylic acid. Examples of dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of dicarboxylic acid derivatives include methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, and maleic acid monoesters such as nonyl maleate, decyl maleate, dodecyl maleate, octadecyl maleate, and fluoroalkyl maleates. Examples of dicarboxylic acid anhydrides include maleic anhydride, acrylic anhydride, methylmaleic anhydride, and dimethylmaleic anhydride. Furthermore, as the carboxylic acid group-containing monomer, an acid anhydride that generates a carboxylic acid group upon hydrolysis can also be used.

[0031] Examples of sulfonic acid group-containing monomers include vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth)allyl sulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, etc. In the present invention, "(meth)allyl" means allyl and / or methallyl.

[0032] Furthermore, examples of the phosphate group-containing monomer include 2-(meth)acryloyloxyethyl phosphate, methyl-2-(meth)acryloyloxyethyl phosphate, ethyl-(meth)acryloyloxyethyl phosphate, etc. In the present invention, "(meth)acryloyl" means acryloyl and / or methacryloyl.

[0033] These acidic group-containing monomers can be used alone or in combination of two or more. Among these acidic group-containing monomers, carboxylic acid group-containing monomers are preferred, with acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid being preferred, and acrylic acid, methacrylic acid and itaconic acid being more preferred.

[0034] The proportion of the acidic group-containing monomer units contained in the polymer is preferably 1% by mass or more, more preferably 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, when the amount of all monomer units in the polymer is 100% by mass.

[0035] Examples of amide group-containing monomers capable of forming amide group-containing monomer units include (meth)acrylamide, N-methylol(meth)acrylamide, dimethyl(meth)acrylamide, diethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide. Among these, (meth)acrylamide is preferred, and acrylamide is more preferred. These can be used alone or in combination of two or more. In this specification, "(meth)acryl" means acrylic and / or methacrylic.

[0036] The proportion of the amide group-containing monomer units contained in the polymer is preferably 1% by mass or more, more preferably 3% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, when the amount of all monomer units in the polymer is 100% by mass.

[0037] The glass transition point of the polymer is preferably −100° C. or higher, more preferably −90° C. or higher, and is preferably 30° C. or lower, and more preferably 10° C. or lower. When the glass transition point of the polymer is the above upper limit or lower, the resulting electrode can exhibit good peel strength. In the present invention, the glass transition point of the polymer can be measured according to the method described in the examples of this specification.

[0038] [Properties of Particulate Polymer] The particulate polymer contained in the binder composition has a volume average particle diameter Da of preferably 50 nm or more, more preferably 100 nm or more, and preferably 200 nm or less, and more preferably 150 nm or less, when measured by a laser diffraction scattering method with the solid content concentration of the binder composition set to 0.1 mass %.

[0039] Furthermore, the particulate polymer contained in the binder composition preferably has an average particle diameter Db of 150 nm or more, more preferably 200 nm or more, and is preferably 300 nm or less, and more preferably 250 nm or less, when measured by dynamic light scattering at a solids concentration of the binder composition of 0.005 mass %.

[0040] The ratio (Da / Db) of the volume average particle diameter Da measured by laser diffraction scattering to the average particle diameter Db measured by dynamic light scattering is preferably 1.4 or more, more preferably 1.5 or more, even more preferably 1.6 or more, and preferably 2.0 or less, more preferably 1.9 or less, and even more preferably 1.8 or less. If Da / Db is equal to or greater than the lower limit, the particulate polymer can adequately cover the surface of the electrode active material, thereby further improving the high-temperature storage characteristics of the secondary battery. Furthermore, if Da / Db is equal to or less than the upper limit, the particulate polymer can exhibit good binding strength in the electrode mixture layer, thereby further improving the cycle characteristics of the secondary battery.

[0041] The particulate polymer preferably has an electrolyte swelling degree of 110% by mass or more, more preferably 120% by mass or more, and preferably 300% by mass or less, more preferably 150% by mass or less, and even more preferably 140% by mass or less. When the electrolyte swelling degree of the particulate polymer is within the above range, the cell characteristics of the secondary battery can be improved.

[0042] The volume average particle diameter Da, the average particle diameter Db and the swelling degree in an electrolyte solution of the particulate polymer can be adjusted, for example, by changing the preparation conditions of the particulate polymer, the structure of the particulate polymer and the composition of the polymer constituting the particulate polymer.

[0043] [One embodiment of particulate polymer] The particulate polymer contained in the binder composition is not particularly limited, but preferably contains a polymer A containing aromatic vinyl monomer units and conjugated diene monomer units, and a polymer B containing aromatic vinyl monomer units and conjugated diene monomer units and different from polymer A. Specifically, the particulate polymer preferably contains particles containing polymer A and particles containing polymer B. Note that the particles containing polymer A and the particles containing polymer B usually exist as separate particles in the binder composition without being composited.

[0044] -Particles Containing Polymer A- Polymer A contains aromatic vinyl monomer units and conjugated diene monomer units, and may optionally contain other monomer units.

[0045] Here, the aromatic vinyl monomer units, conjugated diene monomer units, and other monomer units of polymer A may be the same as those described above with respect to the polymer contained in the particulate polymer, and therefore, description thereof will be omitted here.

[0046] Among these, polymer A preferably contains an aromatic vinyl monomer unit, a conjugated diene monomer unit, a carboxylic acid group-containing monomer unit, and an amide group-containing monomer unit, and more preferably contains a styrene unit, a butadiene unit, an acrylic acid unit, a methacrylic acid unit, and an acrylamide unit.

[0047] When the amount of all monomer units in polymer A is taken as 100% by mass, the proportion of each monomer unit contained in polymer A is preferably as follows. That is, the proportion of aromatic vinyl monomer units in polymer A is preferably 40% by mass or more, more preferably 45% by mass or more, and preferably 55% by mass or less, and more preferably 50% by mass or less. The proportion of conjugated diene monomer units in polymer A is preferably 25% by mass or more, more preferably 30% by mass or more, and preferably 40% by mass or less, and more preferably 35% by mass or less. Furthermore, the proportion of carboxylic acid group-containing monomer units in polymer A is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 20% by mass or less, and more preferably 15% by mass or less. The proportion of amide group-containing monomer units in polymer A is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 10% by mass or less, and more preferably 7% by mass or less.

[0048] Furthermore, polymer A preferably has a higher glass transition point than polymer B, and the glass transition point of polymer A is preferably -10°C or higher, more preferably 0°C or higher, and preferably 30°C or lower, more preferably 10°C or lower. When the glass transition point of polymer A is within the above range, the resulting electrode can exhibit good peel strength. In the present invention, the glass transition point of polymer A can be measured using the method described in the examples of this specification.

[0049] Furthermore, the particles containing polymer A preferably have a volume average particle diameter Da of 100 nm or more, more preferably 130 nm or more, and preferably 200 nm or less, more preferably 150 nm or less, when measured by a laser diffraction scattering method in an aqueous dispersion having a solid content of 0.1% by mass. In the present invention, the volume average particle diameter Da of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0050] Furthermore, the particles containing polymer A preferably have an average particle diameter Db of 200 nm or more, more preferably 220 nm or more, and preferably 300 nm or less, more preferably 250 nm or less, when measured by dynamic light scattering in an aqueous dispersion having a solid content of 0.005% by mass. In the present invention, the average particle diameter Db of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0051] Furthermore, the particles containing polymer A preferably have an electrolyte swelling degree of 110% by mass or more, more preferably 130% by mass or more, and preferably 150% by mass or less, and more preferably 140% by mass or less. If the electrolyte swelling degree of the particles containing polymer A is within the above range, the cell characteristics of the secondary battery can be improved. In the present invention, the electrolyte swelling degree of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0052] Furthermore, the particles containing polymer A preferably have a gel content of 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 99.9% by mass or less, more preferably 99% by mass or less. If the gel content is within the above range, the internal resistance of the secondary battery can be reduced. In the present invention, the gel content of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0053] Furthermore, the particles containing polymer A preferably have a storage modulus of 2.00 MPa or more, more preferably 2.40 MPa or more, even more preferably 2.60 MPa or more, and preferably 3.00 MPa or less, and more preferably 2.90 MPa or less. If the storage modulus of the particles containing polymer A is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the storage modulus of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0054] Furthermore, the particles containing polymer A preferably have a loss modulus of 1.00 MPa or more, more preferably 1.20 MPa or more, and preferably 1.60 MPa or less, more preferably 1.50 MPa or less, and even more preferably 1.45 MPa or less. If the loss modulus of the particles containing polymer A is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the loss modulus of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0055] The particles containing polymer A preferably have a larger loss tangent tanδ value than the particles containing polymer B, and the loss tangent tanδ value of the particles containing polymer A is preferably 0.40 or more, more preferably 0.45 or more, preferably 0.75 or less, more preferably 0.60 or less, and even more preferably 0.55 or less. If the loss tangent tanδ value of the particles containing polymer A is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the loss tangent tanδ value of the particles containing polymer A can be measured using the method described in the examples of this specification.

[0056] The volume average particle diameter Da and average particle diameter Db of the particles containing polymer A can be adjusted, for example, by changing the preparation conditions of the particles containing polymer A. The glass transition temperature, electrolyte swelling degree, gel content, storage modulus, loss modulus, and loss tangent tanδ of the particles containing polymer A can be adjusted, for example, by changing the preparation conditions of the particles containing polymer A, the structure of the particles containing polymer A, and the composition of polymer A.

[0057] —Particles Containing Polymer B— Polymer B contains aromatic vinyl monomer units and conjugated diene monomer units, and may optionally contain other monomer units.

[0058] Here, the aromatic vinyl monomer units, conjugated diene monomer units, and other monomer units of polymer B may be the same as those described above with respect to the polymer contained in the particulate polymer, and therefore, description thereof will be omitted here.

[0059] Among these, polymer B preferably contains aromatic vinyl monomer units, conjugated diene monomer units and carboxylic acid group-containing monomer units, and more preferably contains styrene units, butadiene units and methacrylic acid units.

[0060] When the amount of all monomer units in polymer B is taken as 100% by mass, the proportion of each monomer unit contained in polymer B is preferably as follows. That is, the proportion of aromatic vinyl monomer units in polymer B is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 40% by mass or less, and more preferably 30% by mass or less. Furthermore, the proportion of conjugated diene monomer units in polymer B is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 90% by mass or less, and more preferably 75% by mass or less. Furthermore, the proportion of carboxylic acid group-containing monomer units in polymer B is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 5% by mass or less, and more preferably 4% by mass or less.

[0061] Furthermore, the glass transition point of polymer B is preferably −70° C. or higher, more preferably −60° C. or higher, and preferably −30° C. or lower, more preferably −50° C. or lower. When the glass transition point of polymer B is within the above range, the resulting electrode can exhibit good peel strength. In the present invention, the glass transition point of polymer B can be measured using the method described in the examples of this specification.

[0062] Furthermore, the particles containing polymer B preferably have a volume average particle diameter Da of 90 nm or more, more preferably 100 nm or more, and preferably 130 nm or less, and more preferably 120 nm or less, when measured by a laser diffraction scattering method in an aqueous dispersion having a solid content of 0.1% by mass. In the present invention, the volume average particle diameter Da of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0063] The particles containing polymer B preferably have an average particle diameter Db of 180 nm or more, more preferably 200 nm or more, and preferably 230 nm or less, and more preferably 220 nm or less, when measured by dynamic light scattering in an aqueous dispersion having a solid content of 0.005% by mass. In the present invention, the average particle diameter Db of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0064] Furthermore, the particles containing polymer B preferably have an electrolyte swelling degree of 110% by mass or more, more preferably 120% by mass or more, and preferably 150% by mass or less, and more preferably 140% by mass or less. If the electrolyte swelling degree of the particles containing polymer B is within the above range, the cell characteristics of the secondary battery can be improved. In the present invention, the electrolyte swelling degree of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0065] Furthermore, the particles containing polymer B preferably have a gel content of 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, and preferably 99% by mass or less, and more preferably 95% by mass or less. If the gel content is within the above range, the internal resistance of the secondary battery can be reduced. In the present invention, the gel content of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0066] Furthermore, the particles containing polymer B preferably have a storage modulus of 0.40 MPa or more, more preferably 0.45 MPa or more, even more preferably 0.55 MPa or more, and preferably 0.70 MPa or less, and more preferably 0.60 MPa or less. If the storage modulus of the particles containing polymer B is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the storage modulus of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0067] Furthermore, the particles containing polymer B preferably have a loss modulus of 0.01 MPa or more, more preferably 0.05 MPa or more, and preferably 0.07 MPa or less, and more preferably 0.06 MPa or less. If the loss modulus of the particles containing polymer B is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the loss modulus of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0068] The particles containing polymer B preferably have a loss tangent tanδ of 0.05 or more, more preferably 0.10 or more, and preferably 0.30 or less, more preferably 0.20 or less, and even more preferably 0.13 or less. If the loss tangent tanδ of the particles containing polymer B is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the loss tangent tanδ of the particles containing polymer B can be measured using the method described in the examples of this specification.

[0069] The volume average particle diameter Da and average particle diameter Db of the particles containing polymer B can be adjusted, for example, by changing the preparation conditions of the particles containing polymer B. The glass transition temperature, electrolyte swelling degree, gel content, storage modulus, loss modulus, and loss tangent tanδ of the particles containing polymer B can be adjusted, for example, by changing the preparation conditions of the particles containing polymer B, the structure of the particles containing polymer B, and the composition of polymer B.

[0070] -Mixing Ratio- The ratio of the particles containing polymer B to the total of the particles containing polymer A and the particles containing polymer B (= {particles containing polymer B / (particles containing polymer A+particles containing polymer B)} × 100%) is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. When the ratio of the particles containing polymer B is equal to or greater than the above lower limit, the peel strength of the obtained electrode can be increased. When the ratio of the particles containing polymer B is equal to or less than the above upper limit, the internal resistance of the secondary battery can be further reduced.

[0071] [Method for Preparing Particulate Polymer] The particulate polymer including the above-mentioned polymer can be polymerized according to a known polymerization method, for example, a solution polymerization method, a suspension polymerization method, a bulk polymerization method, an emulsion polymerization method, etc. As the polymerization reaction, addition polymerization such as ionic polymerization, radical polymerization, living radical polymerization, etc. can be used.

[0072] During the polymerization reaction, a molecular weight modifier (chain transfer agent) may be used to adjust the gel content within a preferred range. Commonly used additives such as emulsifiers, dispersants, polymerization initiators, and polymerization aids may also be used. The amounts of these additives used may be the amounts commonly used.

[0073] <Other Components> The binder composition of the present invention may contain components other than the above components (other components) within the scope of the present invention. Examples of other components include antioxidants, antifoaming agents, dispersants, etc. One type of other component may be used alone, or two or more types may be used in combination at any ratio.

[0074] <Properties of Binder Composition> The binder composition must have a gel content of more than 75% by mass and not more than 99.9% by mass, preferably not less than 85% by mass, more preferably not less than 95% by mass, and not more than 99% by mass. If the gel content is within the above range, elution of the particulate polymer into the electrolyte solution can be suppressed, and the internal resistance of the secondary battery can be reduced.

[0075] Furthermore, the binder composition preferably has a storage modulus of 0.20 MPa or more, more preferably 0.50 MPa or more, and even more preferably 1.00 MPa or more, and preferably 3.00 MPa or less, and more preferably 2.50 MPa or less. If the storage modulus of the binder composition is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the storage modulus of the binder composition can be measured using the method described in the examples of this specification.

[0076] Furthermore, the binder composition preferably has a loss modulus of 0.01 MPa or more, more preferably 0.10 MPa or more, even more preferably 0.30 MPa or more, and preferably 1.50 MPa or less, and more preferably 1.00 MPa or less. If the loss modulus of the binder composition is within the above range, the internal resistance of the secondary battery can be further reduced. In the present invention, the loss modulus of the binder composition can be measured using the method described in the examples of this specification.

[0077] The binder composition must have a loss tangent tanδ of 0.001 or more and less than 0.40, preferably 0.10 or more, more preferably 0.24 or more, preferably 0.37 or less, more preferably 0.31 or less, and even more preferably 0.26 or less. When the loss tangent tanδ of the binder composition is equal to or greater than the above-mentioned lower limit, the particulate polymer can be spread appropriately over the surface of the electrode active material, thereby suppressing an increase in the internal resistance of the secondary battery and improving the high-temperature storage characteristics. When the loss tangent tanδ of the binder composition is equal to or less than the above-mentioned upper limit, the particulate polymer can be prevented from excessively covering the surface of the electrode active material, thereby suppressing an increase in the internal resistance of the secondary battery and improving the high-temperature storage characteristics. Furthermore, when the loss tangent tanδ of the binder composition is equal to or less than the above-mentioned upper limit, the particulate polymer can be prevented from excessively covering the surface of the electrode active material, thereby suppressing an increase in the internal resistance of the secondary battery and improving the high-temperature storage characteristics due to its high elasticity, thereby improving the cycle characteristics.

[0078] The gel content, storage modulus, loss modulus and loss tangent tan δ of the binder composition can be adjusted, for example, by changing the composition and preparation conditions of the particulate polymer.

[0079] <Method for preparing binder composition> The binder composition of the present invention is not particularly limited, and can be prepared by mixing the particulate polymer and other components, etc., which are optionally used, in the presence of water. When the binder composition is prepared using an aqueous dispersion of the particulate polymer, the water contained in the dispersion may be used as a dispersion medium for the binder composition as it is.

[0080] (Slurry Composition for Non-Aqueous Secondary Battery Electrodes) The slurry composition for non-aqueous secondary battery electrodes of the present invention is a composition used to form an electrode mixture layer, and contains an electrode active material and the binder composition for non-aqueous secondary battery electrodes of the present invention described above, and optionally further contains other components. That is, the slurry composition for non-aqueous secondary battery electrodes of the present invention typically contains an electrode active material, the particulate polymer described above, and water as a dispersion medium, and optionally further contains other components. Furthermore, since the slurry composition of the present invention contains the binder composition described above, it is possible to prepare a non-aqueous secondary battery electrode that can form a non-aqueous secondary battery having excellent high-temperature storage properties and low internal resistance. Note that, below, as an example, a case where the slurry composition for non-aqueous secondary battery electrodes is a slurry composition for lithium-ion secondary battery negative electrodes will be described, but the present invention is not limited to the following example.

[0081] <Electrode active material> An electrode active material is a material that transfers electrons at an electrode of a secondary battery. A material that can absorb and release lithium is usually used as the negative electrode active material for a lithium ion secondary battery. Specific examples of the negative electrode active material for a lithium ion secondary battery include carbon-based negative electrode active materials, metal-based negative electrode active materials, and negative electrode active materials that are a combination of these.

[0082] Here, the carbon-based negative electrode active material refers to an active material having carbon as the main skeleton into which lithium can be inserted (also referred to as "doped"). Examples of the carbon-based negative electrode active material include carbonaceous materials and graphite materials.

[0083] Examples of carbonaceous materials include graphitizable carbon and non-graphitizable carbon, which has a structure similar to an amorphous structure, such as glassy carbon. Examples of graphitizable carbon include carbon materials made from tar pitch obtained from petroleum or coal. Specific examples include coke, mesocarbon microbeads (MCMB), mesophase pitch-based carbon fiber, and pyrolytic vapor-grown carbon fiber. Examples of non-graphitizable carbon include phenolic resin calcined bodies, polyacrylonitrile-based carbon fibers, pseudoisotropic carbon, furfuryl alcohol resin calcined bodies (PFA), and hard carbon.

[0084] Furthermore, examples of graphite materials include natural graphite, artificial graphite, etc. Here, examples of artificial graphite include artificial graphite obtained by heat-treating carbon containing easily graphitized carbon mainly at 2800°C or higher, graphitized MCMB obtained by heat-treating MCMB at 2000°C or higher, and graphitized mesophase pitch-based carbon fiber obtained by heat-treating mesophase pitch-based carbon fiber at 2000°C or higher.

[0085] Furthermore, the term "metal-based negative electrode active material" refers to an active material containing a metal, typically containing an element capable of inserting lithium in its structure, and having a theoretical electrical capacity per unit mass of 500 mAh / g or more when lithium is inserted. Examples of metal-based active materials include lithium metal, elemental metals capable of forming lithium alloys (e.g., Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, Sr, Zn, Ti, etc.), and alloys thereof, as well as oxides, sulfides, nitrides, silicides, carbides, phosphides, etc., thereof. Among these, active materials containing silicon (silicon-based negative electrode active materials) are preferred as metal-based negative electrode active materials. By using a silicon-based negative electrode active material, the output characteristics and capacity of the resulting non-aqueous secondary battery can be improved.

[0086] Examples of silicon-based negative electrode active materials include silicon (Si), silicon-containing alloys, SiO, and SiO ｘand a composite of a Si-containing material and conductive carbon, which is obtained by coating or compounding a Si-containing material with conductive carbon. These silicon-based negative electrode active materials may be used alone or in combination of two or more.

[0087] <Binder composition> The binder composition of the present invention described above can be used as the binder composition. The content of the predetermined particulate polymer in the slurry composition can be, for example, 0.5 parts by mass or more and 15 parts by mass or less in terms of solid content per 100 parts by mass of the electrode active material.

[0088] <Other Components> Other components that can be blended into the slurry composition are not particularly limited, and include the same components as the other components that can be blended into the binder composition of the present invention. The slurry composition may further contain a conductive material such as carbon black. These components may be used alone or in combination of two or more in any ratio.

[0089] <Preparation of Slurry Composition for Non-Aqueous Secondary Battery Electrode> The above-described slurry composition can be prepared by mixing the above-described components by a known mixing method, for example, using a mixer such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, or a Filmix.

[0090] (Electrode for non-aqueous secondary battery) The electrode of the present invention comprises an electrode mixture layer formed using the above-mentioned slurry composition of the present invention, and typically includes a current collector and an electrode mixture layer formed on the current collector. The electrode mixture layer is typically a layer formed by drying the slurry composition of the present invention, and contains at least an electrode active material and a polymer derived from the particulate polymer, and optionally contains other components. In the electrode mixture layer, the polymer derived from the particulate polymer may be in a particulate form (i.e., the particulate polymer may be contained in the electrode mixture layer as is), or may have any other form.

[0091] Furthermore, since the electrode of the present invention is produced using the slurry composition of the present invention, it is possible to reduce the internal resistance of the secondary battery while allowing the secondary battery to exhibit excellent high-temperature storage characteristics.

[0092] <Method for Forming Electrode> The electrode of the present invention can be produced, for example, through (1) a step of applying a slurry composition onto a current collector (application step), (2) a step of drying the slurry composition applied onto the current collector to form a dried slurry (drying step), and (3) a step of pressing the dried slurry on the current collector (pressing step).

[0093] <<Coating Step>> The method for applying the slurry composition onto the current collector is not particularly limited, and known methods can be used. Specifically, examples of the application method include a doctor blade method, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method. During application, the slurry composition may be applied to only one side of the current collector, or may be applied to both sides. The thickness of the slurry film on the current collector after application and before drying can be appropriately set depending on the thickness of the electrode mixture layer to be obtained.

[0094] <<Drying Step>> The method for drying the slurry composition on the current collector is not particularly limited and any known method can be used, including drying with warm air, hot air, or low-humidity air, vacuum drying, and drying by irradiation with infrared rays, electron beams, etc. By drying the slurry composition on the current collector in this manner, a dried slurry is formed on the current collector.

[0095] <<Pressing Step>> The method for pressing the dried slurry on the current collector is not particularly limited, and can be performed using a known pressing device. Among them, pressing with a press roll (roll pressing) is preferred from the viewpoint of pressing the dried slurry quickly and efficiently. By undergoing the pressing step, the density of the electrode mixture layer can be increased and the adhesion between the electrode mixture layer and the current collector can be improved.

[0096] (Nonaqueous secondary battery) The nonaqueous secondary battery of the present invention includes the nonaqueous secondary battery electrode of the present invention. More specifically, the nonaqueous secondary battery of the present invention includes a positive electrode, a negative electrode, an electrolyte, and a separator, and uses the nonaqueous secondary battery electrode of the present invention as at least one of the positive electrode and the negative electrode, preferably the negative electrode. Furthermore, since the nonaqueous secondary battery of the present invention includes the nonaqueous secondary battery electrode of the present invention, it has excellent high-temperature storage characteristics and low internal resistance. In the following, a case where the secondary battery is a lithium-ion secondary battery will be described as an example, but the present invention is not limited to the following example.

[0097] <Electrode> As described above, the secondary battery electrode of the present invention is used as at least one of the positive electrode and the negative electrode. That is, the positive electrode of the lithium ion secondary battery may be the electrode of the present invention and the negative electrode may be another known negative electrode, the negative electrode of the lithium ion secondary battery may be the electrode of the present invention and the positive electrode may be another known positive electrode, or both the positive electrode and the negative electrode of the lithium ion secondary battery may be the electrode of the present invention. Note that, as a known electrode other than the secondary battery electrode of the present invention, an electrode obtained by forming an electrode mixture layer on a current collector using a known manufacturing method can be used.

[0098] <Electrolyte> As the electrolyte, an organic electrolyte solution in which a supporting electrolyte is dissolved in an organic solvent is usually used. For example, in a lithium ion secondary battery, a lithium salt is used as the supporting electrolyte. For example, LiPF ６ , LiAsF ６ , LiBF ４ , LiSbF ６ , LiAlCl ４ , LiClO ４ , C.F. ３ SO ３ Li, C ４ F ９ SO ３ Li, CF ３ COOLi, (CF ３ CO) ２ NLi, (CF ３ SO ２ ) ２ NLi, (C ２ F ５ SO２ Among them, LiPF is particularly preferred because it is easily soluble in solvents and shows a high degree of dissociation. ６ , LiClO ４ , C.F. ３ SO ３ Li is preferred. Note that one type of electrolyte may be used alone, or two or more types may be used in combination. Generally, the lithium ion conductivity tends to increase as the supporting electrolyte with a higher degree of dissociation is used, so the lithium ion conductivity can be adjusted by the type of supporting electrolyte.

[0099] The organic solvent used in the electrolyte is not particularly limited as long as it can dissolve the supporting electrolyte. For example, in lithium ion secondary batteries, carbonates such as dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate (BC), and ethyl methyl carbonate (EMC) are preferably used; esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; and sulfur-containing compounds such as sulfolane and dimethyl sulfoxide. Mixtures of these solvents may also be used. Among these, carbonates are preferred because of their high dielectric constant and wide stable potential range. The concentration of the electrolyte in the electrolyte can be adjusted as appropriate. Known additives may also be added to the electrolyte.

[0100] <Separator> The separator is not particularly limited, and for example, the separators described in JP 2012-204303 A can be used. Among these, a microporous film made of a polyolefin resin (polyethylene, polypropylene, polybutene, polyvinyl chloride) is preferred because it allows the thickness of the entire separator to be thin, thereby increasing the proportion of electrode active material in the secondary battery and increasing the capacity per volume.

[0101] <Method for Manufacturing Non-Aqueous Secondary Battery> The non-aqueous secondary battery of the present invention can be manufactured, for example, by stacking a positive electrode and a negative electrode with a separator interposed therebetween, rolling or folding the stack as necessary according to the battery shape, placing the stack in a battery container, injecting an electrolyte into the battery container, and sealing the container. At least one of the positive electrode and the negative electrode is an electrode for the non-aqueous secondary battery of the present invention. To prevent internal pressure increases, overcharge / discharge, and the like, a fuse, an overcurrent prevention element such as a PTC element, an expanded metal, a lead plate, or the like may be provided as necessary. The shape of the secondary battery may be, for example, a coin type, a button type, a sheet type, a cylindrical type, a rectangular type, a flat type, or the like.

[0102] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0103] In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. In addition, in a polymer produced by polymerizing multiple types of monomers, the proportion of a monomer unit formed by polymerizing a certain monomer in the polymer usually coincides with the ratio (feed ratio) of the certain monomer to all the monomers used in the polymerization of the polymer, unless otherwise specified. In the examples and comparative examples, various evaluations and measurements were carried out as follows.

[0104] <Volume average particle diameter Da measured by laser diffraction scattering method> Using a particle size distribution analyzer (manufactured by Shimadzu Corporation, product name "SALD-2300") that uses laser diffraction scattering as its measurement principle, the particle size distribution (volume basis) of a measurement sample was measured in accordance with JIS Z8825, and the particle diameter (D50) at which the cumulative volume calculated from the smallest diameter side in the measured particle size distribution becomes 50% was defined as the average particle diameter Da. Note that, as the measurement samples, an aqueous dispersion of a polymer adjusted to a solids concentration of 0.1% by mass and a binder composition adjusted to a solids concentration of 0.1% by mass were used. <Average Particle Diameter Db Measured by Dynamic Light Scattering> The particle size distribution of the measurement sample was measured using a particle size distribution analyzer (manufactured by Otsuka Electronics Co., Ltd., model "FPAR-1000") that uses dynamic light scattering as its measurement principle. The particle diameter (D50) at which the cumulative frequency of light scattering intensity calculated from the small diameter side in the measured particle size distribution reached 50% was defined as the average particle diameter Db. The measurement samples used were an aqueous dispersion of a polymer adjusted to a solids concentration of 0.005% by mass using ion-exchanged water, and a binder composition adjusted to a solids concentration of 0.005% by mass using ion-exchanged water. The measurement conditions for the dynamic light scattering method were as follows: Dispersion medium: Water Measurement temperature: 25°C Measurement concentration (solids content): 0.005% by mass Scattering angle: 160° Light source laser wavelength: 632.8 nm <Glass transition temperature> A water dispersion of the polymer to be measured was dried to prepare a measurement sample. Next, a differential scanning calorimetry (DSC) measurement apparatus (manufactured by SII NanoTechnology Inc., product name "EXSTAR DSC6220") was used. 10 mg of the measurement sample was weighed into an aluminum pan, and an empty aluminum pan was used as a reference. Measurements were performed in accordance with JIS K7121 under measurement conditions of a temperature range of -100°C to 100°C and a heating rate of 10°C / min, to obtain a differential scanning calorimetry (DSC) curve. During this heating process, the glass transition point was determined from the intersection of the baseline immediately before the appearance of the endothermic peak of the DSC curve at which the differential signal (DDSC) was 0.05 mW / min / mg or more, and the tangent to the DSC curve at the first inflection point that appeared after the endothermic peak. <Gel Content (THF-Insoluble Amount)> First, the measurement sample (aqueous dispersion of polymer or binder composition) was dropped into a Petri dish so that the solid content was 1.5 g.The film was then dried for 24 hours in an environment of 22 to 25°C, and further dried for 1 hour at 110°C to obtain a film. The film was then cut into 2.5 mm square pieces, and approximately 0.3 g was precisely weighed. The mass of the film piece obtained by cutting was designated W0. The film piece was then immersed in 80 mL of tetrahydrofuran (THF) at 25°C for 24 hours. The film piece was then removed from the THF and vacuum-dried at 105°C for 3 hours, and the mass of the film piece, W1, was measured. The gel content (amount insoluble in THF) was then calculated according to the following formula: Gel content (mass%) = (W1 / W0) x 100 <Electrolyte Swelling Degree> First, the measurement sample (aqueous polymer dispersion or binder composition) was dried in an environment of 50% humidity and 23 to 25°C to form a film with a thickness of 1 ± 0.3 mm, and then dried in a vacuum dryer at 60°C for 10 hours to obtain a film. Next, this film was cut and approximately 1 g was weighed. The mass of the obtained film piece was designated as W0. This film piece was placed in an environment at a temperature of 60°C using 1.0 M LiPF as an electrolyte. ６The film piece was immersed in a solution (a mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 3 / 7 (mass ratio), containing 2 mass % vinylene carbonate and 2 mass % fluoroethylene carbonate as additives) for 3 days to allow swelling. The film piece was then removed, the electrolyte solution on the surface was wiped with a Kimwipe, and the mass was measured. The mass of the swollen film piece was designated W1. The electrolyte swelling degree was then calculated using the following formula: Electrolyte swelling degree (mass %) = (W1 / W0) × 100 <storage modulus, loss modulus, and loss tangent tanδ> [Preparation of Polymer Film] A measurement sample (aqueous polymer dispersion or binder composition) was weighed onto a Teflon petri dish so that the thickness after drying would be 50 μm. The sample was then vacuum dried at room temperature for 12 hours to obtain a polymer film. [Measurement of Viscoelasticity of Polymer Film] Using the polymer film prepared above, the storage modulus and loss modulus were measured at angular frequencies of 0.5 to 60 rad / s at 20°C and 25% strain using a viscoelasticity measuring device (manufactured by Anton Paar, product name "MCR301"). Furthermore, the loss tangent tanδ was calculated based on the measurement results at an angular frequency of 30 rad / s. <Peel Strength> The negative electrodes prepared in the Examples and Comparative Examples were cut into rectangular shapes measuring 100 mm in length and 10 mm in width to prepare test specimens. The obtained test specimens were placed with the surface of the negative electrode composite layer facing downward, and cellophane tape was attached to the surface of the negative electrode composite layer. Cellophane tape specified in JIS Z1522 was used as the cellophane tape. The cellophane tape was fixed to a test table. Then, one end of the current collector was pulled vertically upward at a pulling rate of 150 mm / min, and the stress when peeled was measured. This measurement was performed three times, and the average value was calculated as the peel strength, which was evaluated according to the following criteria. A higher peel strength indicates a stronger binding force of the negative electrode mixture layer to the current collector, i.e., a higher adhesion strength. A: Peel strength of 8 N / m or more B: Peel strength of 7 N / m or more but less than 8 N / m C: Peel strength of less than 7 N / m <Cycle Characteristics of Secondary Battery> The cycle characteristics were evaluated using the secondary batteries produced in the examples and comparative examples. Specifically, the secondary batteries were first left to stand at a temperature of 25°C for 6 hours.Next, the battery was charged for 100 minutes at a constant current of 0.1 C in a 25°C environment. Then, an aging treatment was performed for 12 hours in a 60°C environment. Next, the battery was charged to a cell voltage of 4.20 V at a constant current of 0.5 C in a 25°C environment, and discharged to a cell voltage of 2.75 V, and the initial capacity C0 was measured. This charge / discharge cycle was further repeated, and the capacity C1 after 100 cycles was measured. The capacity retention C2 was calculated according to the following formula: C2 (%) = (C1 / C0) x 100. The cycle characteristics were evaluated according to the following criteria. A: Capacity retention C2 was 92% or more. B: Capacity retention C2 was 87% or more but less than 92%. C: Capacity retention C2 was less than 87%. <Internal Resistance of Secondary Battery> IV resistance was measured using the secondary batteries fabricated in the examples and comparative examples. Specifically, the battery was first charged at a charge rate of 0.1 C at 25 ° C until the voltage reached 4.2 V, then rested for 10 minutes, and then CV discharged to 3.0 V at a discharge rate of 0.1 C three times. This conditioning process was then performed. Subsequently, the battery was charged to 3.75 V at 1 C (C is a value expressed as rated capacity (mA) / 1 hour (h)) in a −10 ° C atmosphere, and then charged and discharged for 15 seconds at 0.5 C, 1.0 C, 1.5 C, and 2.0 C, centered on 3.75 V. The battery voltage after 15 seconds on the charge side in each case was plotted against the current value, and the slope was determined as the IV resistance (charge IV resistance). The obtained IV resistance values ​​(Ω) were evaluated according to the following criteria. The smaller the IV resistance value, the lower the internal resistance of the secondary battery and the better its low-temperature characteristics. A: IV resistance is 15Ω or less B: IV resistance is more than 15Ω and less than 17Ω C: IV resistance is more than 17Ω and less than 19Ω D: IV resistance is more than 19Ω <High-temperature storage characteristics of secondary battery> The fabricated secondary battery was charged to a cell voltage of 4.2V by a constant current method of 0.5C in an atmosphere of 25°C, and then discharged to 3.0V, and the initial discharge capacity C0 was measured. Next, the secondary battery was charged to a cell voltage of 4.2V by a constant current method of 0.5C in an atmosphere of 25°C. Thereafter, this secondary battery was stored in an atmosphere of 60°C for 3 weeks (high-temperature storage).After high-temperature storage, the battery was discharged to 3 V using a constant current method of 0.5 C to measure the remaining capacity C1 after high-temperature storage. The capacity retention rate (%) = (remaining capacity C1 / initial discharge capacity C0) x 100 was then calculated and evaluated according to the following criteria. A higher capacity retention rate indicates better high-temperature storage characteristics of the secondary battery. A: Capacity retention rate is 90% or more. B: Capacity retention rate is 80% or more but less than 90%. C: Capacity retention rate is less than 80%.

[0105] Example 1 Preparation of Binder Composition Production of Particles Comprising Polymer A 2.1 parts of styrene as an aromatic vinyl monomer, 3.3 parts of 1,3-butadiene as a conjugated diene monomer, 0.1 parts of methacrylic acid as a carboxylic acid group-containing monomer, 0.23 parts of dodecyl diphenyl ether disulfonic acid sodium salt as an emulsifier, 15 parts of ion-exchanged water, and 0.02 parts of potassium persulfate as a polymerization initiator were placed in a 5 MPa pressure vessel A equipped with a stirrer to obtain a mixture A. The obtained mixture A was thoroughly stirred and then heated to 57°C to initiate polymerization and reacted for 5 hours, and then heated to 70°C and reacted for an additional 4 hours to obtain seed particles. Separately, 46.6 parts of styrene as an aromatic vinyl monomer, 29 parts of 1,3-butadiene as a conjugated diene monomer, 14.2 parts of acrylic acid as a carboxylic acid group-containing monomer, 4.7 parts of acrylamide as an amide group-containing monomer, 0.5 parts of tert-dodecyl mercaptan as a molecular weight modifier, 0.20 parts of sodium lauryl sulfate as an emulsifier, and 44 parts of ion-exchanged water were added to a 5 MPa pressure vessel B equipped with a stirrer to obtain a mixture B. After obtaining the seed particles, the temperature of the contents of the pressure vessel A was raised to 75°C, and mixture B was added to the pressure vessel A over 5 hours. At the same time, polymerization was initiated by starting the addition of 0.48 parts of potassium persulfate as a polymerization initiator to the heat-resistant vessel A. That is, the overall monomer composition was 48.7 parts of styrene, 32.3 parts of 1,3-butadiene, 14.2 parts of acrylic acid, 4.7 parts of acrylamide, and 0.1 part of methacrylic acid. Five hours after the start of polymerization, the addition of the entire mixture containing these monomer compositions was completed, and then 0.5 parts of potassium persulfate was added as a polymerization initiator. The mixture was then heated to 90°C and reacted for 4 hours. When the polymerization conversion rate reached 97%, the mixture was cooled to stop the reaction. A 5% aqueous solution of sodium hydroxide was added to the mixture containing the polymer to adjust the pH to 8. Unreacted monomers were then removed by heating and distillation under reduced pressure. The mixture was then cooled to obtain an aqueous dispersion containing polymer A. Various measurements and evaluations were performed using the obtained aqueous dispersion. The results are shown in Table 1.[Preparation of Particles Containing Polymer B] First, in the first-stage polymerization, 25 parts of styrene as an aromatic vinyl monomer, 72 parts of 1,3-butadiene as a conjugated diene monomer, 100 parts of ion-exchanged water, 0.7 parts of dodecylbenzenesulfonic acid as an emulsifier, 0.1 parts of α-methylstyrene dimer as a chain transfer agent (molecular weight modifier), and 0.3 parts of potassium persulfate as a polymerization initiator were placed in a 5 MPa pressure vessel equipped with a stirrer and thoroughly stirred. The mixture was then heated to 60°C to initiate polymerization. The polymerization was continued until the polymerization conversion rate reached 96%. Next, in the second-stage polymerization, 3 parts of methacrylic acid as a carboxylic acid group-containing monomer and 37 parts of ion-exchanged water were continuously added to the same pressure vessel under stirring to form the shell portion, and the polymerization was continued. This aqueous dispersion was heated to 70°C, and when the polymerization conversion rate reached 97%, the reaction was stopped by cooling. A polymer was formed as a shell on the outer surface of the core, yielding a mixture containing polymer particles having a core-shell structure. Subsequently, unreacted monomers were removed by heated vacuum distillation. A 5% aqueous solution of sodium hydroxide was added to the mixture containing the polymer particles to adjust the pH to 7, yielding an aqueous dispersion containing polymer B. Various measurements and evaluations were performed using the resulting aqueous dispersion. The results are shown in Table 1. [Preparation of Binder Composition] The aqueous dispersion of polymer A and the aqueous dispersion of polymer B were mixed to a solids mass ratio of 9:1 (polymer A:polymer B) to obtain a binder composition (aqueous dispersion). Various measurements and evaluations were performed using the resulting binder composition. The results are shown in Table 1. <Preparation of Negative Electrode Slurry Composition> 87.3 parts of artificial graphite as a carbon-based negative electrode active material and SiO as a silicon-based negative electrode active material were added to a planetary mixer equipped with a disperser. Ｘ9.7 parts of the slurry and 2.0 parts (solid content equivalent) of a carboxymethylcellulose sodium aqueous solution as a thickener were added, and the solid content was adjusted to 61.5% with ion-exchanged water, followed by mixing for 40 minutes at room temperature. After mixing, the solid content was gradually adjusted to 56% and 51% with ion-exchanged water, and 1.0 part (solid content equivalent) of the binder composition obtained as described above was added to obtain a mixed solution. The obtained mixed solution was degassed under reduced pressure to obtain a slurry composition for a negative electrode with good fluidity. <Production of a negative electrode> The above-mentioned slurry composition for a negative electrode was applied to a copper foil (current collector) having a thickness of 16 μm using a comma coater in a coating amount of 10 mg / cm. ２ The copper foil coated with the negative electrode slurry composition was then transported at a speed of 0.5 m / min through an oven at 75°C for 2 minutes and then through an oven at 120°C for 2 minutes, thereby drying the negative electrode slurry composition on the copper foil and obtaining a negative electrode blank. The negative electrode blank was then rolled using a roll press to obtain a negative electrode having a negative electrode composite layer thickness of 80 μm. The peel strength of the obtained negative electrode was evaluated. The results are shown in Table 1. <Production of Positive Electrode> 96 parts of lithium nickel manganese cobalt oxide as the positive electrode active material, 2 parts (solids equivalent) of PVDF (polyvinylidene fluoride) as a binder for the positive electrode composite layer, 2 parts of acetylene black as a conductive material, and 20 parts of N-methylpyrrolidone as a solvent were added and mixed in a planetary mixer to obtain a positive electrode slurry composition. The obtained positive electrode slurry composition was applied to an aluminum foil (current collector) having a thickness of 16 μm using a comma coater in an amount of 24.5 mg / cm after drying. ２The aluminum foil coated with the positive electrode slurry composition was transported at a speed of 0.5 m / min through an oven at 60°C for 2 minutes, and then through an oven at 120°C for 2 minutes, thereby drying the positive electrode slurry composition on the aluminum foil and obtaining a positive electrode blank. The positive electrode blank was rolled using a roll press to obtain a positive electrode having a positive electrode composite layer thickness of 70 μm. <Separator Preparation> A single-layer polypropylene separator (width 65 mm, length 500 mm, thickness 25 μm; manufactured by a dry process; porosity 55%) was prepared. This separator was cut into a 5 cm x 5 cm square and used in the secondary battery described below. <Secondary Battery Fabrication> An aluminum packaging material was prepared as the battery exterior. The positive electrode was cut into a 4 cm x 4 cm square and placed so that the surface on the current collector side was in contact with the aluminum packaging material. Next, the square separator was placed on the surface of the positive electrode composite layer of the positive electrode. Furthermore, the negative electrode was cut into a 4.2 cm × 4.2 cm square, and this was placed on a separator so that the surface on the negative electrode composite layer side faced the separator. ６ A solution (the solvent was a mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 3 / 7 (mass ratio), containing 2 mass% vinylene carbonate and 2 mass% fluoroethylene carbonate as additives) was filled into the battery. Furthermore, to seal the opening of the aluminum packaging, the aluminum packaging exterior was closed by heat sealing at 150°C, producing a laminate cell-type lithium ion secondary battery. The obtained secondary battery was evaluated for cycle characteristics, high-temperature storage characteristics, and internal resistance. The results are shown in Table 1.

[0106] Examples 2 and 3 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that, when preparing the binder composition, an aqueous dispersion of polymer A and an aqueous dispersion of polymer B were mixed so that the mass ratio of the solids (polymer A:polymer B) was 7:3 (Example 2) and 5:5 (Example 3), respectively, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0107] Examples 4 to 6 Binder compositions, negative electrode slurry compositions, negative electrodes, positive electrodes, separators, and secondary batteries were prepared in the same manner as in Examples 1 to 3, except that the amount of tert-dodecyl mercaptan used as a molecular weight modifier during the preparation of particles containing polymer A was changed to 0.3 parts, and further, after the addition of the entire mixture containing the monomer composition was completed (i.e., 5 hours after the start of polymerization), the mixture was heated to 90°C and reacted for 4 hours without adding 0.5 parts of potassium persulfate, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0108] Example 7 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that, when producing particles containing polymer A, the amount of tert-dodecyl mercaptan used as a molecular weight modifier was changed to 1.0 part, and the amount of potassium persulfate used as a polymerization initiator added simultaneously with mixture B was changed from 0.48 part to 0.98 part, and further, when producing particles containing polymer B, the amount of α-methylstyrene dimer used as a chain transfer agent (molecular weight modifier) ​​was changed to 0.5 part, and the amount of potassium persulfate used as a polymerization initiator was changed to 0.5 part. The results are shown in Table 1.

[0109] Example 8 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that a binder composition prepared as follows was used. Measurements and evaluations were then carried out in the same manner as in Example 1. The results are shown in Table 1. <Preparation of Binder Composition> First, in the first stage of polymerization, 4 parts of styrene as an aromatic vinyl monomer for forming a core portion, 91 parts of 1,3-butadiene as a conjugated diene monomer, 100 parts of ion-exchanged water, 0.7 parts of dodecylbenzenesulfonic acid as an emulsifier, 0.1 parts of α-methylstyrene dimer as a chain transfer agent (molecular weight modifier), and 0.3 parts of potassium persulfate as a polymerization initiator were placed in a 5 MPa pressure vessel equipped with a stirrer and thoroughly stirred. The mixture was then heated to 60°C to initiate polymerization. The polymerization was continued until the polymerization conversion rate reached 96%. Next, in the second-stage polymerization, 5 parts of methacrylic acid as a carboxylic acid group-containing monomer and 37 parts of ion-exchanged water were continuously added to the same pressure vessel under stirring to form the shell portion, and the polymerization was continued. This aqueous dispersion was heated to 70 ° C., and when the polymerization conversion rate reached 97%, the reaction was stopped by cooling, and a polymer as a shell portion was formed on the outer surface of the core portion, thereby obtaining a mixture containing polymer particles having a core-shell structure. Thereafter, unreacted monomers were removed by heating and vacuum distillation. A 5% aqueous sodium hydroxide solution was added to the mixture containing the polymer particles, and the pH was adjusted to 7, to obtain an aqueous dispersion (binder composition) containing a polymer (particulate polymer).

[0110] Comparative Example 1 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that the aqueous dispersion containing polymer A was used as the binder composition without using the aqueous dispersion containing polymer B, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0111] Comparative Example 2 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 4, except that the aqueous dispersion containing polymer A was used as the binder composition without using the aqueous dispersion containing polymer B, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0112] Comparative Example 3 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that a binder composition prepared as follows was used. Measurements and evaluations were then performed in the same manner as in Example 1. The results are shown in Table 1. <Preparation of Binder Composition> A reactor was charged with 150 parts of ion-exchanged water, 4 parts of sodium dodecylbenzenesulfonate as an emulsifier, 65 parts of styrene as an aromatic vinyl monomer, 1.5 parts of acrylic acid and 3.5 parts of itaconic acid as carboxylic acid group-containing monomers, and 0.5 parts of t-dodecyl mercaptan as a molecular weight modifier, in this order. Next, the gas inside the reactor was replaced with nitrogen three times, and then 30 parts of 1,3-butadiene as a conjugated diene monomer was charged. 0.5 parts of potassium persulfate as a polymerization initiator was charged into the reactor, which was maintained at 60°C, to initiate the polymerization reaction, which was continued with stirring. When the polymerization conversion rate reached 96%, the mixture was cooled, and 0.1 parts of a hydroquinone aqueous solution (concentration 10%) was added as a polymerization terminator to terminate the polymerization reaction. Thereafter, residual monomers were removed using a rotary evaporator at a water temperature of 60°C, and an aqueous dispersion of a polymer (particulate polymer) was obtained. A 5% aqueous sodium hydroxide solution was added to the mixture containing this particulate polymer, and the pH was adjusted to 8 to obtain a binder composition.

[0113] Comparative Example 4 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were produced in the same manner as in Example 1, except that a binder composition prepared as follows was used, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1. <Preparation of Binder Composition> 1.93 parts of styrene as an aromatic vinyl monomer, 3.08 parts of 1,3-butadiene as a conjugated diene monomer, 0.15 parts of itaconic acid as a carboxylic acid group-containing monomer, 0.2 parts of sodium lauryl sulfate as an emulsifier, 20 parts of ion-exchanged water, and 0.03 parts of potassium persulfate as a polymerization initiator were placed in a 5 MPa pressure vessel A equipped with a stirrer, and the mixture was thoroughly stirred, and then heated to 60°C to initiate polymerization, and the mixture was allowed to react for 6 hours to obtain seed particles. After the above reaction, the mixture was heated to 75 ° C., and 27.54 parts of styrene as an aromatic vinyl monomer, 43.86 parts of 1,3-butadiene as a conjugated diene monomer, 2.07 parts of itaconic acid as a carboxylic acid group-containing monomer, 4.60 parts of acrylonitrile, 14.74 parts of methyl methacrylate, 1.11 parts of acrylamide, 0.27 parts of tert-dodecyl mercaptan as a chain transfer agent, and 0.35 parts of sodium lauryl sulfate as an emulsifier were added from another container B to pressure-resistant container A. At the same time, the second-stage polymerization was initiated by starting the addition of 0.97 parts of potassium persulfate as a polymerization initiator to pressure-resistant container A. Furthermore, 4 hours after the start of the second-stage polymerization (after adding 70% of the entire monomer composition), 0.92 parts of hydroxyethyl acrylate was added to pressure-resistant container A over 1.5 hours. Five and a half hours after the start of the second-stage polymerization, the addition of the entire mixture containing these monomer compositions was completed, and then the mixture was further heated to 85°C and reacted for 6 hours. When the polymerization conversion rate reached 97%, the reaction was stopped by cooling to obtain a mixture containing a particulate polymer. A 5% aqueous solution of sodium hydroxide was added to this mixture containing the particulate polymer to adjust the pH to 8. Thereafter, unreacted monomers were removed by heating and distillation under reduced pressure. Thereafter, the mixture was further cooled to obtain an aqueous dispersion (binder composition) containing the desired particulate polymer.

[0114] Comparative Example 5 A binder composition, a negative electrode slurry composition, a negative electrode, a positive electrode, a separator, and a secondary battery were prepared in the same manner as in Example 1, except that, when producing particles containing polymer A, the amount of tert-dodecyl mercaptan used as a molecular weight modifier was changed to 2.5 parts, and the amount of potassium persulfate used as a polymerization initiator added simultaneously with mixture B was changed from 0.48 parts to 0.98 parts, and further, the aqueous dispersion containing polymer A was used as is as the binder composition without using the aqueous dispersion containing polymer B, and measurements and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0115]

[0116] It can be seen from Table 1 that in Examples 1 to 8, in which the values ​​of loss tangent tan δ and the gel content were within the predetermined ranges, secondary batteries with excellent high-temperature storage characteristics and low internal resistance were obtained. Table 1 also shows that in Comparative Examples 1 to 3, in which the values ​​of loss tangent tan δ were large, the internal resistance of the secondary battery increased, in Comparative Example 4, in which the value of loss tangent tan δ was large and the gel content was low, the internal resistance of the secondary battery increased and the high-temperature storage characteristics decreased, and in Comparative Example 5, in which the gel content was low, the internal resistance of the secondary battery increased.

[0117] According to the present invention, it is possible to provide a binder composition for a non-aqueous secondary battery electrode and a slurry composition for a non-aqueous secondary battery electrode, which are capable of forming a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance. Also, according to the present invention, it is possible to provide an electrode for a non-aqueous secondary battery, which is capable of forming a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance. And according to the present invention, it is possible to provide a non-aqueous secondary battery having excellent high-temperature storage characteristics and low internal resistance.

Claims

1. A binder composition for non-aqueous secondary battery electrodes, comprising a particulate polymer and water, wherein the particulate polymer comprises a polymer containing aromatic vinyl monomer units and conjugated diene monomer units, the binder composition has a loss tangent tanδ value of 0.001 or more and less than 0.40, and a gel content of more than 75 mass% and not more than 99.9 mass%.

2. The binder composition for non-aqueous secondary battery electrodes according to claim 1, wherein the ratio (Da / Db) of the volume average particle diameter Da of the particulate polymer measured by a laser diffraction scattering method at a solid content concentration of 0.1 mass % to the average particle diameter Db of the particulate polymer measured by a dynamic light scattering method at a solid content concentration of 0.005 mass % is 1.4 or more and 2.0 or less.

3. The binder composition for a non-aqueous secondary battery electrode according to claim 1, wherein the loss tangent tan δ is 0.15 or more.

4. The binder composition for a non-aqueous secondary battery electrode according to claim 1, wherein the particulate polymer comprises: a polymer A containing an aromatic vinyl monomer unit and a conjugated diene monomer unit; and a polymer B containing an aromatic vinyl monomer unit and a conjugated diene monomer unit and different from the polymer A.

5. The binder composition for a non-aqueous secondary battery electrode according to claim 1, wherein the particulate polymer has a degree of swelling in an electrolyte of 300 mass % or less.

6. A slurry composition for a non-aqueous secondary battery electrode, comprising an electrode active material and the binder composition for a non-aqueous secondary battery electrode according to any one of claims 1 to 5.

7. The non-aqueous secondary battery electrode slurry composition according to claim 6, wherein the electrode active material comprises a silicon-based negative electrode active material.

8. A non-aqueous secondary battery electrode comprising a current collector and an electrode mixture layer located on the current collector, wherein the electrode mixture layer is a layer formed from the slurry composition for a non-aqueous secondary battery electrode according to claim 6.

9. A non-aqueous secondary battery comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode and the negative electrode is the electrode for a non-aqueous secondary battery according to claim 8.

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